Potato drip irrigation system

ABSTRACT

An arrangement is provided for improving the yield of potato crops. The arrangement includes a bed, a plurality of pairs of parallel rows of potato plants, and a drip irrigation tape. The bed is provided for multiple rows of potato plants. The plurality of pairs of parallel rows of potato plants in the bed have an inter-row gap between the rows in each pair of rows spaced from one another sufficiently to provide a moisture permeable agronomic soil corridor between the rows in each pair of rows to provide a supply of water to a root zone of each row within each pair of rows of potato plants while maintaining aerated soil within and above the agronomic soil corridor to reduce excessively wet conditions adjacent the crop canopy and a solar light corridor provided between adjacent pairs of rows to provide increased solar energy to the potato plants. The drip irrigation tape has emitters provided intermediate rows within each pair of parallel rows of potato plants below a soil surface of the bed in the agronomic soil corridor. A method is also provided.

RELATED PATENT DATA

This patent application is a continuation application of pending U.S.patent application Ser. No. 10/409,981, filed Apr. 8, 2003, entitled“Potato Drip Irrigation System and Method”, naming Brian L. Andersen,Robert Mittelstadt, Michael Andersen, and Gary Christensen as inventors,and which is now U.S. Pat. No. ______ issued ______, the disclosure ofwhich is incorporated by reference.

TECHNICAL FIELD

This invention pertains to plant husbandry. More particularly, thepresent invention relates to potato plant arrangements and methods ofplanting potatoes which improves crop yield and quality.

BACKGROUND OF THE INVENTION

The production of potatoes forms an important portion of the agricultureeconomy of the United States. Potatoes are used for both fresh vegetablemarkets, as well as value-added processed foods. For example, in theUnited States approximately 1.25 million acres of potatoes are plantedeach year. This acreage results in a farm-gate value of 3.06 billiondollars, according to the National Agricultural Statistician Service(NASS) of the U.S. Department of Agriculture (USDA), for year 2001.Within Washington State alone, approximately 160,000 acres of potatoesare grown annually for both domestic and international consumption. Asin any industry, there exists a desire to increase productivity andefficiency in the process of taking a potato crop from a planting stageto a point-of-sale stage.

From the perspective of a grower or farmer, profitability is partly afunction of crop yield, where crop output is maximized relative to inputcosts. Incentives are also an important part of profitability, where agrower is able to produce a crop meeting preset quality criteria. From aprocessing and packing perspective, final end product often defines thedesired size and shape of raw product. For example, a french fryprocessor specializing in long, “steak”-cut style fries will want auniform supply of 10 to 14 ounce potatoes. Likewise, a packer supplyingfresh potatoes to restaurants for baking will want a uniform supply of10 to 12 ounce potatoes with good skin quality. Extra costs are incurredwhen additional sorting, grading and transportation steps are requiredin order to meet the specific needs of particular processors andpackers. Moreover, the additional handling of potatoes can decreasetheir quality due to bruising and other factors. Therefore, for thepacker and processor, there are efficiencies to be gained by providing apotato production system that is specifically designed to deliver aspecific end product. Furthermore, the commercial grower is also in aposition to benefit financially by providing a raw product with highermarket value. The same principles apply in the seed potato industry,where commercial growers desire receiving seed of uniform size and vigorfrom the seed grower. For example, the quality of seed has a greatbearing on the performance and ultimate success of a potato crop.

A vast majority of acreage that is put into potato production each yearin the U.S. is in geographic areas that require full or supplementalirrigation in order to meet crop water requirements. Currentstate-of-the-art in U.S. potato production uses center-pivot irrigationmachines on large fields (typically over 60 acres), in order to makeefficient use of farm equipment. Typically, potatoes are planted in a“hill” system where potato rows are separated by relatively deepfurrows. These hills are typically spaced 34 or 36 inches apartdepending on equipment conventions in the growing region.

Center-pivot irrigation is popular for several reasons. Much of thelabor cost associated with irrigation is eliminated, center-pivotmachines can be adapted to rolling and hilly ground and fertilizer andother products can be delivered in a metered manner through theirrigation water. However, there are disadvantages to center-pivotirrigation systems. One problem is that water is applied from overhead,potentially leading to excessively wet conditions within the crop canopythat tends to increase the potential for disease. Due to the intensityof the irrigation under a center-pivot irrigation device, there is alsoa tendency for the impact of water droplets to “beat down” the soil andcanopy, which has a negative effect on plant health as well.Furthermore, there are limits as to how frequent an area within theirrigated field can receive needed moisture as it depends upon thetraveling speed of the system. These factors do provide some challengesto growing an “above average” crop that suits many target markets.

In order to produce a high yielding crop that is uniform in size, shapeand quality, there exist three primary requirements. First, there existsa need to provide for optimal plant spacing to take advantage ofavailable field area and sunlight. Secondly, there exists a need toprovide a uniform and favorable growing environment, such as a suitableamount of available soil moisture and nutrients. Finally, there exists aneed to keep the plants healthy through maturity.

With a conventional hill planting system, there are severe limitationsto providing optimal plant spacing. This is because the only variablethat can be manipulated is the spacing of potato plants within a row.The spacing between rows is fixed due to the noted conventions inplanting and harvest equipment. It follows that the grower is thereforeunable to specifically and uniformly define the field area occupied byeach plant. Research studies have shown that yield is directly relatedto cumulative intercepted sunlight energy by the plants. Therefore, itis important for the plant canopy (leaf area) to quickly and efficientlycover the field at an early stage in the season and, in doing so, it isalso important that each potato plant “sees” the same amount ofsunlight. A side-benefit of having early ground cover is the moderatingeffect the plant canopy has on temperatures within the canopy and in thesoil, which is conducive to favorable and uniform growing conditions.

In consideration of the second requirement, the ability to “feed” orsupply water and nutrients at the appropriate time and rate isfundamental to supporting steady plant growth and thereby producing ahealthy, uniform crop. In achieving this end, there exists a need for anew, improved technique of drip irrigation that will provide a means bywhich water and nutrients can be delivered directly to the plant rootzone according to the plant's needs. There is an additional need toprovide for the delivery of moisture requirements below the soilsurface, so that excessively wet conditions in the plant canopy can beavoided, thereby mitigating certain disease potential. Lastly, a systemis needed that is capable of producing a high degree of uniformity ofpotato crop field-wide so that each plant is supplied equally with waterand nutrients, including optional fertilizer.

FIG. 1 illustrates a prior art potato irrigation system that usesirrigation drip tape for irrigating beds 10, 12, and 14 of potatoesrepresented by seeds 20 having a maturing canopy 22. Seeds 20 areconfigured in rows 24, 26, 28, and 30. An irrigation drip tape 32 isprovided between the two center rows 26 and 28 of each bed 10, 12, and14. The outer rows 24 and 30 are not optimally irrigated by tape 32because they are spaced apart from tape 32 an unacceptable distancewhich means that outer rows are under-watered (or inner rows areover-watered).

The system of FIG. 1 represents seed potato production at a knownlocation in France using drip irrigation. A soil surface view of thebeds is shown. Seed spacing was 9.7 inches along each row, with fourlines on a 71-inch bed. Plant population was 36,437 plants/acre.

FIG. 2 illustrates a sub-surface view taken just above the irrigationdrip tape within beds 10, 12, and 14. Emitters 34 are shown spaced alongeach tape 32. The inefficient placement of emitters 34 places many seeds(and plant root systems) too far from emitters 34 to optimize plantproduction and effectively reduce disease.

The system and method of potato production presented herein gives agrower an advantage in meeting the above-identified deficiencies.

SUMMARY OF THE INVENTION

An arrangement is provided for improving the growing and the yield ofpotatoes from potato plants.

According to one aspect, an arrangement is provided for improving theyield of potato crops. The arrangement includes a bed, a plurality ofpairs of parallel rows of potato plants, and a drip irrigation tape. Thebed is provided for multiple rows of potato plants. The plurality ofpairs of parallel rows of potato plants in the bed have an inter-row gapbetween the rows in each pair of rows spaced from one anothersufficiently to provide a moisture permeable agronomic soil corridorbetween the rows in each pair of rows to provide a supply of water to aroot zone of each row within each pair of rows of potato plants whilemaintaining aerated soil within and above the agronomic soil corridor toreduce excessively wet conditions adjacent the crop canopy and a solarlight corridor provided between adjacent pairs of rows to provideincreased solar energy to the potato plants. The drip irrigation tapehas emitters provided intermediate rows within each pair of parallelrows of potato plants below a soil surface of the bed in the agronomicsoil corridor.

According to another aspect, an arrangement is provided for improvingthe growing of potato crops. The arrangement includes a bed for multiplerows of potato plants, a plurality of pairs of parallel rows of potatoplants, and a line-source irrigation system comprising a drip irrigationtape. Each of the rows of potato plants has a root zone. The pluralityof pairs of parallel rows of potato plants in the beds have a gapbetween adjacent pairs of rows. Placement of the gap, in combinationwith in-row potato plant spacings, provides for a substantiallyequidistant, equal-area arrangement of light area for a potato plant.The line-source irrigation system includes a drip irrigation tape, withemitters, provided intermediate to each row with each pair of parallelrows of potato plants. The proximity of the emitters and tape isconfigured to provide a substantially equal, uniform and optimal supplyof water to the root zone of each plant within each row whilemaintaining aerated soil conditions about the root zone of each plantand mitigating excessively wet conditions within a canopy of the potatoplants.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described below withreference to the following accompanying drawings.

FIG. 1 is simplified plan view layout of a segment of potato cropaccording to one prior art planting system and method depicting the cropand system adjacent a bed surface.

FIG. 2 is a simplified plan view layout of the prior art system andmethod of FIG. 1 depicting the crop and system beneath the bed surfaceand just above the drip system emitters.

FIG. 3 is a simplified plan view layout of the present system and methodof planting and producing potatoes depicting the crop and systemadjacent a bed surface.

FIG. 4 is a simplified plan view layout of the present system and methodof FIG. 3 depicting the crop and system beneath the bed surface and justabove the drip system emitters.

FIG. 5 is a soil sectional view taken along line 5-5 of FIG. 3 depictingthe layout of seed rows and drip irrigation tape within a potato bed.

FIG. 6 is a rear view illustrating a tractor configured to lay dripirrigation tape within the potato beds of FIGS. 3-5.

FIG. 7 is an enlarged isometric view illustrating one tape deliverysystem used on the tractor of FIG. 6 for laying drip irrigation tape.

FIG. 8 is a simplified schematic and isometric view illustrating aportion of a potato bed from FIGS. 3-5.

FIG. 9 is a simplified isometric view illustrating potato plants growingin the bed of FIGS. 3-5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

This disclosure of the invention is submitted in furtherance of theconstitutional purposes of the U.S. Patent Laws “to promote the progressof science and useful arts” (Article 1, Section 8).

Reference will now be made to a preferred embodiment of Applicants'invention. An exemplary implementation is described below and depictedwith reference to the drawings comprising a system and method (orarrangement) for growing potato crops, as well as improving yield andquality, identified by reference numeral 100. While the invention isdescribed by way of a preferred embodiment, it is understood that thedescription is not intended to limit the invention to such embodiments,but is intended to cover alternatives, equivalents, and modificationswhich may be broader than the embodiments, but which are included withinthe scope of the appended claims.

In an effort to prevent obscuring the invention at hand, only detailsgermane to implementing the invention will be described in great detail,with presently understood peripheral details being incorporated byreference, as needed, as being presently understood in the art.

FIG. 3 depicts potato growing system 10 in simplified, schematic planview showing a portion of three beds 110, 120, and 130 from a field witha soil surface 36 on top of each bed 110, 120, and 130. Within each bed110,120, and 130, individual potato seeds 20 are planted in rows 124,126, 128, and 130. According to one embodiment, a pair of dripirrigation tapes 132 is provided in each bed 110, 112, and 114. Tapes132 are each provided between a pair of adjacent rows 124, 126 and 128,130 such that maximum realized growth plant canopies 22 in adjacent rowsabout each tape 132 are more efficiently realized. Accordingly, duringearlier growth phases prior to maximum maturity, there exists a solarlight corridor 40, 42 as shown in FIG. 9, prior to final maturity andmaximum canopy growth.

Also, relatively wide inter-row gaps 116 and 118 are provided betweenadjacent beds 110, 112 and 112, 114, respectively, as shown in FIGS. 3-5and 9. Gaps 116 and 118 provide for passage of wheels on a tractor 50during seeding of potato plants and also during placement of irrigationtape using a tractor 50, as shown in FIG. 6. Furthermore, relativelynarrow inter-row gaps 117, 119, and 121 are provided between neighboringpairs of rows 124, 126 and 128, 130 in each bed 110, 112, and 114. Gaps117, 119, and 121 are provided in beds 110, 112, and 114 betweenadjacent rows 126 and 128 where an irrigation tape 132 is not provided.

Gaps 116 and 118 typically comprise furrows that are formed by tractorwheels, which means that gaps 116 and 118 can (in some cases) be widerthan gaps 117, 119, and 121. Gaps 117, 119, and 121 are provided withinbeds 110, 112, and 114, respectively, in order to even out lightdistribution amongst individual rows so that all rows will receive asimilar amount of light. If gaps 117, 119, and 121 were not provided,then potato plant rows 124 and 130 would receive a significantly greateramount of sunlight than would rows 126 and 128 which would generate agreater variation in plant growth and potato production, and would leadto non-uniformity that reduces optimal quality and production ofpotatoes.

Additionally, FIG. 9 illustrates immature growth of plants such thatsolar light corridors are provided by gaps 117, 119, and 121 (also seeFIG. 3), in addition to the solar light corridors provided by wheelfurrow gaps 116 and 118. As shown in FIG. 9, moisture permeableagronomic soil corridors are also provided between the rows in each pairof rows, such as between rows 124 and 126, as well as rows 128 and 130,as provided by gaps 40 and 42. Moisture is depicted in such gaps, orcorridors in FIG. 9.

The invention comprises a “bed” system whereby multiple potato rows canbe planted in an arrangement that is optimal for the potato variety anddesired end-product. The arrangement consists of pairs of potato rowsplaced symmetrically within the bed and each pair irrigated by a singleline of drip irrigation tape (or hose), located intermediate to the twoadjacent potato rows. In the preferred embodiment, the bed system iscomprised of four potato rows (two adjacent pairs) but may also bedesigned to accommodate a common multiple of two. This bed system givesthe grower great flexibility in arranging the plant spacing, bothlaterally within the bed and longitudinally down the row. Thisflexibility is important as it allows the grower to plant precisely interms of light area per plant (sunlight energy) and radial distance, forsufficient room within the soil for tubers to develop withoutinterference. In addition, the drip irrigation component provides themeans by which a uniform supply of water and nutrients can be providedwithin the root zone as required by the plant. Furthermore, by limitingthe majority of irrigation to a region below the soil surface,conditions within the crop canopy that are favorable to disease can bemitigated.

FIG. 4 illustrates a simplified plan view layout of the system 100 ofFIG. 3. More particularly, a potato crop and system 100 are illustratedbeneath a soil surface of each bed 110, 112, and 114, just above thedrip irrigation tape 132, and illustrating the positioning and spacingof fluid emitters 134 positioned along each tape 132 relative to potatoseeds 20. The position of gaps 116, 118 and 117, 119, and 121 are alsoshown.

In order to understand the benefits provided by system 100, it isimportant to appreciate certain growth features of potato plants. Apotato plant is a shallow rooted crop that does not respond favorably toextremes in soil moisture, such as where moisture levels are either toowet or too dry. Potato plants grow best when soil moisture is maintainedwithin a narrow range where needed moisture is available, but aerationof the root zone is also maintained. One distinguishing feature ofirrigation drip tape (such as tape 132) is that it employs a turbulentflow path between a main flow channel, or supply tube, and an emitter,or outlet. The emitter track is designed to produce a specific flow rateand depending on the water pressure and emitter spacing, the flow ratefor the tape is defined to optimally deliver water to themoisture-permeable agronomic corridor. With recent advances in drip tapetechnology, very low emitter flows can be achieved, allowing for a soilenvironment adjacent to the tape that is minimally impacted by over-wetconditions. This in turn, allows a potato seed-piece (such as seeds 20)to be placed relatively close to the drip tape where soil moistureconditions are optimally maintained.

FIG. 5 shows an exemplary bed 112 in elevational view taken along line5-5 of FIG. 3. Gaps 116 and 118 for tractor wheels are shown on eitherside of bed 112. Likewise, tapes 132 (and emitters) are providedintermediate each pair of parallel rows of potato plants (identified byseeds 20) below a soil surface 36 of bed 112 in the agronomic soilcorridor. The agronomic soil corridor corresponds with the solar lightcorridors 40 and 42, but is provided directly beneath such corridors,within the respective soil. A plurality of pairs of parallel rows 124,126 and 128, 130 of potato plants (coincident with seeds 20) in bed 112having an inter-row gap 117, 119, and 121 (of FIG. 3) between each pairof rows spaced from one another sufficiently to provide a solar lightcorridor to provide increased solar energy to the potato plants and amoisture permeable agronomic soil corridor 40 and 42 (of FIG. 9) betweenthe pairs of rows and beneath the solar light corridor to provide asupply of water and nutrients to a root zone of each row of a pair ofrows of potato plants while maintaining aerated soil above the agronomicsoil corridor in the solar light corridor to reduce excessively wetconditions adjacent the crop canopy.

A generalized drawing of the preferred embodiment is given in FIG. 5.More particularly, dimension A represents a distance between tractorwheels defining the width of bed 112, dimension B represents thedistance between the interior potato rows 126 and 128, and dimension Crepresents the lateral distance between the drip tape 132 and seed piece(potato row) 20.

According to one construction, common bed widths (dimension A) for thisproduction system can range from 68 inches to 108 inches, for fourpotato rows 124, 126, 128, and 130, depending on various factors such aspotato variety and intended market, equipment availability and climate.The bed width, A, is defined by the distance between the tractor wheelfurrows provided by gaps 116 and 118.

According to another construction, greater bed widths are also possible,in order to accommodate a total of six rows and three lines of tape inan alternative embodiment of the invention employing the same geometry.

Another dimension used to define bed 112, dimension B, will range from14 inches on smaller beds to 34 inches for the 102 inch bed according tothe one construction. Finally, dimension C will range from 7 to 11inches, depending on the bed width chosen.

In order to further define the geometry of bed 112, the ratio ofdimension C to the average tape spacing (half of dimension A) will rangefrom 0.13 to 0.25. Secondly, the combination of dimensions B and C willbe such that the horizontal areas, represented by the inside and outsideseed pieces, will not differ by more than 30 percent. This is importantin order to ensure that both sunlight energy and agronomic requirements(soil moisture and fertility) are balanced between the inside potatorows 126, 128 and the outside potato rows 124 and 130.

With potato production system 100, it has been determined that theaverage area required for each plant (square feet of sunlight per plant)can be decreased from what is conventionally believed to be ideal atapproximately 2.7 square feet per plant (for russet potatoes). Fieldobservations in a commercial production setting with this system haveshown that average areas per plant can range from 1.6 to 2.3 squarefeet, depending on the potato variety and target market. This isapproaching 15% less space per plant. Depending on the bed width, thein-row spacing (seed piece drop down the row) can be adjusted to meetthe space requirements. Furthermore, the in-row spacings may bedifferent between the inside and outside rows in order to achieve theproper space requirements for each row. Optionally, seeds in adjacentrows can be offset so that a seed in one row is midway between adjacentseeds in an adjacent row (in a longitudinal direction of the rows).

There is one more parameter to define potato production system 100, therate at which irrigation water is supplied to each potato row 124, 126,128, and 130 by the irrigation drip tape 132. As mentioned previously,tape flow is typically defined in terms of the volume of water per unitper unit length of drip tape. In English units, the tape flow iscommonly given as gallons per minute per 100 feet. The drip tape flowsspecified for this production system will range from a nominal flow of0.110 to 0.220 gpm/100 ft, depending mainly on the bed width and soiltexture (is one example). To define the parameter of interest, both thedrip tape flow and dimension C are used to calculate a theoretical rateof flux at the seed piece, based on a circle of radius C whose center islocated at the tape. For this production system, the flux will rangefrom 0.004 to 0.017 inches per hour at the seed piece. This parameter isimportant in that it defines the optimal region for seed piece placementin terms of the drip tape chosen.

FIG. 6 shows a tractor 50 including a tool bar 52 configured to layirrigation drip tape within beds of a potato field. More particularly,four irrigation drip tape carrier and delivery systems 54 are carried bytool bar 52 for simultaneously laying tapes 132 of bed 112 and tape 132of rows 128 and 130 of bed 110 and tape 132 of rows 124 and 126 of bed114 (see FIG. 3). Tape 132 between rows 124 and 126 of bed 110 and tape132 between rows 128 and 130 of bed 114 are laid in a prior andsubsequent pass using tractor 50.

FIG. 7 depicts one construction for tape carrier and delivery system 54.More particularly, system 54 includes a self-unwinding tape spool 56 onwhich a roll of tape is stored. A hollow delivery tube 58 of system 54allows passage of irrigation drip tape 132 from reel 56 into soil wheretape 132 exists from a tape injection shoe 60. Shoe 60 has awedge-shaped leading end that moves soil to provide for deposition oftape 132 beneath a soil surface. Preferably, tape 132 is secured at afree end to a position in a field, prior to starting movement of atractor. Once secured, tape 132 is withdrawn from each system 54 as thetractor moves down a field.

FIG. 8 shows in simplified schematic view system 100 within a portion ofbed 112. More particularly, tape 132 is found to be optimally placed inorder to maximize health and production of potato crop from plants grownfrom seeds 20. Such optimization results from the adjacent proximity ofeach seed 20 along tape 132 and the associated emitters. By way of oneexample, seeds 20 are provided below soil surface 36 of bed 112 adistance of 4 to 7 inches. An aerated soil zone 25 is 80 percent of thedistance of 4-7 inches (see FIG. 8), according to one construction.Seeds 20 are provided a distance of 7 to 11 inches from tape 132. Asemi-cylindrical agronomic zone is shown extending around tape 132within which water (and fertilizer) can be provided for optimal growthto potato plant roots from seeds 20.

FIG. 9 depicts in simplified isometric view potato plants growing in thebeds of FIGS. 3-5, such as bed 112. Gaps 116 and 118 clearly showclearance room for tractor wheels between adjacent beds which typicallyform furrows. A central irrigation pipe 232 feeds water (and optionallyfertilizer) to individual irrigation drip tapes 132 that are optimallypositioned between rows of potato plants, such as rows 1224, 126, 128,and 130. Each plant is illustrated in a middle growth stage where canopy22 is not fully mature. Hence, light corridors can be seen withincorridors 40 and 42, as well as within gap 119. Gaps 116 and 118 (aswell as gap 119) provide further light corridors between adjacent rowsof potato plants that are provided in adjacent beds.

In summary, the present potato production system includes a crop bed, aplurality of row pairs of potato plants and a line-source irrigationsystem. The crop bed is defined by the distance between tractor wheels,or the respective furrows formed thereby. A plurality of pairs of potatoplant rows are located within each bed. Each row pair is defined by aplane of symmetry vertically situated at a drip irrigation tape (orhose) located intermediate to the row pair, the proximity of which, incombination with the plant spacing in the row, sufficiently provides foran “equidistant and equal area” arrangement in a Cartesian plane on thebed surface. The plurality of row pairs are placed in a symmetricalarrangement within each bed so as to further provide for equal solarlight per plant. A line-source irrigation system includes the dripirrigation tape (or hose), with emitters, provided intermediate to eachpair of parallel rows of potato plants, the proximity of which providesfor an equal, uniform and optimal supply of water and nutrients to theplant root zone while maintaining aerated soil conditions and mitigatingexcessively wet conditions within the crop canopy.

Supporting field data has been generated and is provided here. Theavailability of data for comparison is limited, but some yield and gradeinformation is available from field trials as well as from the USDA NASSfor Washington, Oregon and Idaho in 2002 (Potato Stocks, Objective YieldSurvey). Though not resulting from a direct comparison in the field,this data helps to show the relative improvements that are possible inyield, uniformity of size and grade.

One parameter of interest is the percent of potatoes above 6 ounceswhere a high value is desirable. Table 1 shows that the percent ofpotatoes above 6 ounces are 67.9 and 79.0 percent respectively for NASSsurvey samples from Washington and from the field employing theproduction system of the invention. Secondly, it can be seen that thereis a higher percentage of potato tubers falling in the central 8-12ounce category and lower percentages in the extreme size categories,indicating an improvement in the size distribution (30.4 and 43.8percent respectively) in view of the target size. Table 2 shows acomparison of the grade, which is indicative of the uniformity of sizeand shape of the potatoes and, consequently, is reflective of theuniformity of growing conditions during the growing season. Lastly,Table 3 shows the average potato yield in Washington State, based on2002 NASS statistics, in comparison with the payable yield from theproduction system of the invention, in this instance showing a 40percent increase. TABLE 1 Potato size distribution comparison for russettype potatoes. Data from NASS for Washington State in 2002 and fromfield trials employing the production system of the invention forUmatilla Russets. Ounces Size <4 4-6 6 7 8 9 10 11 12 13 >14 %Washington 9.0 23.1 9.6 9.7 8.7 6.8 5.7 5.0 4.2 3.9 19.1 Invention 7.513.5 8.2 7.2 13.6 9.7 6.6 7.8 6.1 3.4 16.5

TABLE 2 Potato grade distribution comparison for russet type potatoes.Data from NASS for Washington State in 2002 and from the potatoprocessor for Umatilla Russet product received from the field employingthe production system of the invention. US No. 1 US No. 2 Cull Total %Washington 72.0 26.5 1.5 100.0 Invention 93.0 5.6 1.4 100.0

TABLE 3 Potato yield comparison for russet type potatoes. Data from NASSfor Washington State in 2002 (Potato Stocks) and from potato processoras reported on contract incentive summary for Umatilla Russet. Yieldcwt/ac tons/ac Washington (avg) 544 27.2 Invention 784 39.2

In compliance with the statute, the invention has been described inlanguage more or less specific as to structural and methodical features.It is to be understood, however, that the invention is not limited tothe specific features shown and described, since the means hereindisclosed comprise preferred forms of putting the invention into effect.The invention is, therefore, claimed in any of its forms ormodifications within the proper scope of the appended claimsappropriately interpreted in accordance with the doctrine ofequivalents.

The invention claimed is:
 1. An arrangement for improving the yield ofpotato crops, comprising: a bed for multiple rows of potato plants; aplurality of pairs of parallel and adjacent rows of potato plants in thebed during an immature plant canopy phase having an inter-row gapbetween the rows in each pair of rows spaced from one anothersufficiently to provide a fluid permeable agronomic soil corridorbetween the rows in each pair of rows that provides substantiallyunsaturated hydraulic communication between the emitters and thecircumjacent root zone and to provide a supply of water to a root zoneof each row within each pair of rows of potato plants while maintainingaeration within and above the agronomic soil corridor to reduceexcessively wet conditions adjacent the canopy and having a solar lightcorridor provided between adjacent pairs of rows to provide increasedsolar energy to the potato plants; and a fluid delivery line withintermittent emitters provided between the rows within each pair ofparallel rows of potato plants beneath a soil surface of the bed in theagronomic soil corridor.